A new yearlong study of weight loss in overweight or obese women identified three key strategies for taking off unwanted pounds. The No. 1 tip for success? Writing down everything you eat or drink in a food journal.

Also: don’t skip meals and avoid eating out at restaurants too often. Underlying all three strategies is a sense of mindfulness, the authors say — being acutely aware and accountable for every morsel you eat. “It is difficult to make changes to your diet when you are not paying close attention to what you are eating,” said study author Dr. Anne McTiernan, director of the Fred Hutchinson Cancer Research Center, in a statement.

The study of 123 sedentary postmenopausal women aged 50 to 75 randomly assigned participants to one of two weight-loss plans: restricted-calorie diet only, or exercise plus diet. The women filled out a series of questionnaires detailing their dietary intake, any eating-related weight-loss strategies they used, meal patterns and other behaviors like eating out or food journaling. They also filled out a 120-item food frequency questionnaire to track dietary changes from the beginning to the end of the one-year study.

On average, women in both groups lost weight, about 11% of their starting weight, or 19 lbs., which met the study’s goals. But McTiernan and her colleagues noticed that certain strategies the women used were associated with more weight loss.

Women who kept food journals consistently lost about 6 lbs. more than those who did not, for example, likely because they held themselves responsible for everything they ate, the authors said. Food journaling isn’t easy or convenient, but done consistently, it can help steer dieters to more healthful choices since it allows people not only to keep track of calories, but also to gauge the overall quality of their diet. The authors advise dieters to write down absolutely everything in their food journals, including condiments, toppings and sauces, and always to keep track of portions. Women in the study were given printed booklets to use as their food journals, but people can use anything they like, from low-tech notebook and pen to ready-made apps on their iPhone or tablet.

Women who reported skipping meals lost nearly 8 lbs. less than women who ate regularly. The authors think that when people skip meals, they’re more likely to binge eat or eat fattening foods later on, causing them to eat more calories overall. Habitual meal-skipping or fasting could also affect the body’s metabolism, discouraging weight loss. “We also think skipping meals might cluster together with other behaviors. For instance, the lack of time and effort spent on planning and preparing meals may lead a person to skip meals and/or eat out more,” said McTiernan.

Indeed, women who ate out more lost less weight, especially those who frequently ate out for lunch. Women who had lunch out at least once a week lost about 5 lbs. less than those who didn’t eat out as often. Again, the problem is lack of awareness and control over what you’re eating, the authors said: you can’t control what goes into restaurant dishes or how they’re cooked, and you also have no say over portion size.

For anyone thinking of starting a food journal, the authors have some helpful tips:

Be honest: record everything you eat

Be accurate: measure portions, read labels

Be complete: include details such as how the food was prepared, and the addition of any toppings or condiments

Be consistent: always carry your food diary with you or use a diet-tracking application on your smartphone

“We think our findings are promising because it shows that basic strategies such as maintaining food journals, eating out less often and eating at regular intervals are simple tools that postmenopausal women — a group commonly at greater risk for weight gain — can use to help them lose weight successfully,” McTiernan said.

The study was published in the Journal of the Academy of Nutrition and Dietetics.